Chapter 6.2, Problem 8E

To determine

To compute: The indicated calculations $\text{AB}$ and $\text{BA}$, if $\text{A}=\left(\begin{array}{cccc}1& t& \cos t& \sin t\\ 0& 1& -\sin t& \cos t\\ 0& 0& -\cos t& -\sin t\\ 0& 0& \sin t& -\cos t\end{array}\right)$ and $\text{B}=\left(\begin{array}{cccc}1& -t& 1& -t\\ 0& 1& 0& 1\\ 0& 0& -\cos t& \sin t\\ 0& 0& -\sin t& -\cos t\end{array}\right)$.